Long Integrated Bragg Gratings for SoI Wafer Metrology

Author

Ayotte, Nicolas ; Simard, Alexandre D. ; LaRochelle, Sophie

Author_Institution

Dept. of Electr. & Comput. EngineeringCOPL, Univ. Laval, Quebec City, QC, Canada

Volume

27

Issue

7

fYear

2015

fDate

April1, 1 2015

Firstpage

755

Lastpage

758

Abstract

Phase-sensitive photonic devices fabricated in silicon-on-insulator platform can have their response significantly modified by wafer height fluctuations. In this letter, we demonstrate a novel metrology technique for measuring on-chip thickness variations using long integrated chirped Bragg gratings. Thickness variations are recovered from the measurement of the complex transmission and reflection spectra using an inverse scattering algorithm. With 1-cm long sidewall gratings on 1.2-μm wide waveguides, we measure waveguide height variations with nanometer-scale precision and tens of micrometer of longitudinal resolution. The results are confirmed by atomic force microscopy measurements.

Keywords

Bragg gratings; atomic force microscopy; height measurement; infrared spectra; integrated optoelectronics; light scattering; optical waveguides; silicon-on-insulator; thickness measurement; SOI wafer metrology; atomic force microscopy; inverse scattering algorithm; long integrated chirped Bragg gratings; longitudinal resolution; nanometer-scale precision; on-chip thickness variation measurement; phase-sensitive photonic devices; reflection spectra; sidewall gratings; silicon-on-insulator platform; size 1 cm; size 1.2 mum; transmission spectra; wafer height fluctuation; waveguide height variation measurement; Bragg gratings; Chirp; Gratings; Loss measurement; Optical waveguides; Reflection; Semiconductor device measurement; Bragg gratings; Integrated optics; Meteorology; Nanophotonics; Nanophotonics.; Nanotechnology; Silicon on insulator technology; meteorology; nanotechnology; silicon on insulator technology;

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/LPT.2015.2391174

Filename

7006638